And I'm tickled pink you are deep into the observer problem! Fascinating subject, I've been meditating about it also.
And I'm so glad that you do, Alamo-Girl! As you say, there is something eerie about "the unreasonable effectiveness of mathematics" as a sort of "mirror image" of physics. We can "see" through mathematics, especially geometry, the things that we cannot see with our eyes. String theory would be "out of business" absent this understanding. And string theory is quite respectable in the scientific community these days.
Notwithstanding that string theory is thoroughly Platonic in spirit. :^) As are most string theorists, if Lisa Randall's observation is correct.
Thank you so much for writing, dear sister!